*{
    margin: 0;
    padding: 0;
}
.nav{
    text-align: center;
    margin-top: 30px;
}
.xz .active{
    border-bottom: 1px solid orangered;
}
.xz li{
    list-style: none;
    display: inline;
    padding-left: 5px;
    padding-right: 5px;
    cursor: pointer;
}
.xz li:hover{
    border-bottom: 1px solid orangered;
}
.main{
    margin-top: 6px;
    font-size: 12px;
}
.bs{
    color: orangered;
}
.main div{
    display: none;
}
.main .active{
    display: block;
}